Sanitary Napkin with Braid

ABSTRACT

The present invention relates to a sanitary napkin whose securing means includes a braid of absorbent material. The braid structure maximizes absorbency, while minimizing bulk and thus allows the pad to be comfortably held in place during use, in much the same way that the popular thong underwear are held.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of U.S. application Ser.No. 12/440,920 filed Mar. 11, 2009, which is a 35 U.S.C. Section 371 ofPCT/US2007/078171 filed Sep. 11, 2007, which claims priority to U.S.Provisional Application No. 60/825,244 filed Sep. 11, 2006, which areincorporated herein by reference in their entirety.

FEDERALLY SPONSORED RESEARCH

Not applicable.

REFERENCE TO MICROFICHE APPENDIX

Not applicable.

FIELD OF THE INVENTION

The invention relates to sanitary napkins improved with an extendingbraid, to be worn like a thong. The braid provides much improvedabsorbency protection and fit, and yet is comfortable to wear.

BACKGROUND OF THE INVENTION

The effectiveness of external feminine sanitary protection products suchas sanitary napkins depends upon a good fit, which serves to minimizediscomfort and provide the maximum absorbent surface area. However,despite the importance of fit to sanitary protection, most prior artnapkins are secured either by adhesion to an undergarment or rely on theuse of belts, safety pins or clips and other attachment means. Typicallythe undergarment itself doesn't fit well, and even if it does, nothingprevents the pad from bunching and minimizing the absorbent surfacearea. Further, the adhesives often fail, and the pad shifts and fails inits primary task. Belts provide greater security, but they are bulky,restrictive, uncomfortable, and few women use them.

A variety of sanitary products have employed some type of projection toassist in either or both of fluid absorption and fit. U.S. Pat. No.7,056,312 describes a sanitary napkin with an absorbent tab disposed atan obtuse angle to the napkin body. U.S. Pat. No. 6,997,915 describes apad including a substantially planar strip adapted to be receivedbetween the buttocks of the wearer to thereby help hold the pad inplace. U.S. Pat. No. 5,127,911 describes a sanitary napkin with a stringthat, when pulled, draws together the longitudinal edges of the napkinand forms a contoured projection. U.S. Pat. No. 5,169,394 describes asanitary napkin having an elongated absorbing member whereby one end isslidably attached to the pad to allow adjustment of the fit. U.S. Pat.No. 4,533,357 describes napkin having a flexible tab portion shaped tocomfortably fit between the buttocks of the wearer. U.S. Pat. No.5,743,896 describes a sanitary napkin having a protrusion insertablebetween the buttocks of a wearer. EP1332744 describes a sanitary napkinwith a gluteal groove strip. U.S. Pat. No. 6,613,031 describes asanitary napkin having a tail strip extending rearwardly, again to fitbetween the buttocks. Finally, WO9004956 describes a sanitary napkinhaving an absorbent stub piece, again to fit between the buttocks.

However, each of these suffers from the same disadvantage, in that theprotrusion is either too bulky for comfort, or if sufficiently slenderfor comfort, then it lacks sufficient absorbency. What is needed in theart is a napkin that is both comfortable and sufficiently absorbent.

SUMMARY OF THE INVENTION

The invention provides a sanitary napkin which achieves a dynamic bodyfit because the pad is securely held in place by a braid positionedtoward the middle of the pad. An intergluteal strip or “braid” ofabsorbent material maximizes absorbency, while minimizing bulk. Thebraid allows the pad to be comfortably held in place during use, in muchthe same way that the popular thong underwear are held, and provides asecure yet comfortable fit. Further, the braid has superior absorbencyand improves the functioning of the pad.

In one embodiment, the sanitary napkin has a pad body having anelongated shape and having an absorbent core between an inner liner anda outer liner. There may also be a barrier layer that may be integralwith the outer liner or may be a separate layer, and the sanitary napkincan also include wings and/or adhesives. An elongated braid extendsupwardly from the pad body, generally positioned centrally or in theback half of the pad body. The braid is made of at least three strandsof braided fiber and is absorbent. The braid can be made from two ormore different fibers, one of which is absorbent, and can includecotton. The braid can be a diamond braid having a hollow core and anabsorbent material filling the hollow core, or can be a solid braid. Thebraid can be stitched, glued, melted, welded or otherwise adhered to thepad body (FIG. 1). It can be stitched to the outer liner of the pad body(8) and protrude through the absorbent core and inner liner, it can beattached to the absorbent core (7) or it can be attached to the innerliner of the pad body (6).

A “sanitary pad” or “sanitary napkin” is a disposable absorbent pad usedto absorb urine, uterine flow during menstruation, post surgery fluids,and post partum fluids. Sanitary pads may also be referred to as anadult diaper, incontinence pad, post surgical diaper, post partumdiaper, maximum absorbency pad or sanitary napkin. The sanitary pad hasan inner surface, a core, and an outer surface. The “inner” surface isclosest the skin of the wearer and the “outer” surface touches thewearers clothing.

By “braid” or “braided” what is meant is that one or more separatestrands of material are knitted, braided, plaited or woven to form aseries of “interlocking loops.” This provides maximum strength andabsorbency, while minimizing bulk.

Braiding is well known in the art, and any braid pattern may be used,including the simple tri-strand braid commonly used to braid hair.However, a locking braid can be used where it is contemplated that theuser will trim the braid length for best fit. In a preferred embodiment,the braid forms a hollow tube, which can then be filled with anextremely absorbent core material or super-absorbent material. In otherembodiments, at least two different kinds of fibers are used to make thebraid, the first fiber selected for absorbency and the second fiberselected for strength. Thus the composite braid will exhibit the best ofboth features without sacrificing either. In yet another preferredembodiment, the braid will include stretchable fibers, and thus thebraid itself will be stretchable.

Fibers may be constructed of natural, manufactured, synthetic or blendedmaterials. Fibers may be fabrics, threads, yams or other formedmaterials. Natural materials include, but are not limited to, cotton,hemp, wool, wood-pulp or other natural materials. Manufactured fiberslike cellulose may be processed to increase absorbency or change thetexture of the material. Synthetic materials may include polyacrylate,polypropylene, polyester, polyethylene, polyurethane, and LYCRA™. In oneembodiment a super-absorbent is incorporated into the material. Inanother embodiment a wicking material is incorporated to facilitate themovement of moisture.

Examples of suitable braiding are described in U.S. Pat. No. 3,911,785,U.S. Pat. No. 3,975,980, U.S. Pat. No. 4,016,911, U.S. Pat. No.4,380,949, U.S. Pat. No. 5,067,384, U.S. Pat. No. 5,060,549,US2005229770, US2005277088, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A-D. Side view showing a braid secured to the pad.

FIG. 2. Top view showing major and minor axis. The braid (3) is attached(2) to the pad (1) along the major axis from the median (A) to the rearof the pad (C). The pad may be tapered (C) for a more comfortable fit. Aouter barrier can be created by sewing or binding the pad to create aridge (4).

FIG. 3. Perspective View.

FIG. 4. Various braid styles demonstrating Solid, Hollow, Double,Diamond, and Plait braids. Braiding of a simple three strand plait isshown.

FIG. 5. A disposable sanitary pad and thong underwear is demonstrated.The pad (1) is attached (2) to the braid (3) which can then be eitherformed integrally with or attached at 90.degree. (9) to a (circular)waistband (5).

FIG. 6A-B. Close up of exemplary braid structure with large braid nearthe pad, and a smaller or thinner braid at the opposite end.

FIG. 7. Photograph of examplary embodiment.

FIG. 8. Table showing increased absorbency contributed by braid of10-40%. Pad weighed with the braid attached; placed under running waterfor ten seconds, drained for an additional ten seconds and weighed withand without braid.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention is generally directed to an improved hygienic pad thatincorporates a braided tail or stem to eliminate leakage, even on heavyflow days. The braid is worn between the buttocks, in a manner similarto that seen with a thong bikini The braid is configured to be soft,flexible, and will shape itself to a woman's anatomy. In someembodiments, the braid can taper from the thickest point at or near thepad body to the thinnest point at the end of the braid. The braidstructure allows it to have sufficient strength, even when of minimalsize, thus ensuring an enduring fit. Further, with the proper selectionof materials, both strength and absorbency can be achieved withoutincurring bulk and thus sacrificing comfort. In some embodiments, thebraid ranges from 10 to 30 cm in length, preferably it is from 15-25 cm,and most preferably the braid is left long enough for the wearer to trimto comfort.

The pad is made in any manner known in the art. The reader is referredto napkin art and copious diaper art for teachings on the constructionof absorbent articles including patents U.S. Pat. No. 7,235,708, U.S.Pat. No. 7,196,241, U.S. Pat. No. 7,1476,28, U.S. Pat. No. 6,821,270 andU.S. Pat. No. 6,676,649. In a preferred embodiment, the pad includes aninner dry lining, an absorbent core, and an outer barrier layer. The padmay also include a second outer lining for improved aesthetics,especially when the pad is made as a disposable panty/pad. In apreferred embodiment, the pad materials will be biodegradable.

Standard sanitary napkins have a inner or top sheet, core, and outer orbottom sheet. Standard inner sheet materials can be inexpensive,nonwoven topsheet or sophisticated three-dimensional films that providea unidirectional moisture barrier. Core materials directly affect padsize and absorbency. Acquisition layers, fluff pulp, and airlaid corescan be used to increase absorbency. Standard fluff requires morematerial to achieve the same absorbency as high-density fluff mixed withsuper absorbent polymer (SAP) granule powder. SAP is a white powder thatnot only absorbs moisture instantaneously upon contact, but also holdsthat moisture securely. Some super absorbent powders can absorb 400 to1,000 times their own weight in pure water, or 30 to 70 times their ownweight in urine. Fluff layers with integrated SAP powder can provide upto 60% cost savings for raw material, increasing absorbency whiledecreasing bulk and cost. In one embodiment the SAP can be polyacrylatepolymers with a variety of crosslinking and associated salts includingsodium polyacrylate, microporous cellulose, carbohydrate acryliccopolymer, or other highly absorbent material. Ultrathin cores, with orwithout binders, provide a number of fluff layers with an integrated SAPpowder. One or more intermediary acquisition layers between the topsheetand core materials may be used to provide additional protection andabsorbency. Customized sanitary napkins include tri-fold, singlewrapping, with or without wings, and thong pantyliners with an attachedwaist.

The pad can be any shaped designed for comfort, which typically includesgenerally oval, rectangular, triangular, hour-glass, and variationsthereof with somewhat concave sides. Size can vary according to flow,with heavy flow requiring a longer and/or thicker pad. Size may also beadjusted also according to a woman's size, including petite or juniorsizes that are correspondingly smaller than a woman's pad. The pad maybe any length and in one embodiment pads range from 10 to 50 cm lengths.The pad may also be 10, 15, 20, 25, 30, 35, 40, 45 or 50 cm in length.Wings may be added to the sides of the pad, as well as adhesives to thebottom and/or wings that secure the pad to an undergarment.

The braid should be attached at or near the midpoint of the minor axisof the pad, its exact position along the major axis depends on the shapeand length of the pad. Thus, in a thong-like underwear or pad (FIG. 2C),the braid can be more rearward, but in the traditional rectangular padit can be centrally located along both axis (FIG. 2A), although it canalso tend towards the back half of the major axis of the pad (FIG. 2B).In one embodiment the braid is placed in the middle of the minor andmajor axes as shown in FIG. 2A. In another embodiment the braid isplaced in the center of the minor axis and 3-5 cm from the rear of themajor axis. In another embodiment the braid is placed at 1, 2, 3, 4, 5,6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 cm from the rear of the majoraxis. The braid may also be placed a portion of the distance from therear of the major axis. The braid may be placed ½ or midway along themajor axis (FIG. 2A), thus the braid is in the exact middle of the pad.The braid may also be placed at ⅓ of the total length, thus the braidwould be placed at 10 cm on a 30 cm pad or at 5 cm on a 15 cm pad. Thebraid may also be placed at ¼, ⅕, ⅙, 1/7, 2/7, 3/7, ⅛, ⅜, or ⅝ the totaldistance from the rear of the pad.

The braid can be used without any attachment means but may also beattached to the wearer or an undergarment. Adhesives can be used on theouter surface of the braid, or to the end of the braid, allowing secureattachment to either the wearer or the undergarment. Alternatively, thebraid can attach to an elastic waistband, or may include an attachmentmeans (such as Velcro or a hook), allowing it to feed over the wearer'sthong back and attach to itself.

The braid will be attached to the pad in any manner known in the art.The braid may be attached to the inner liner (FIG. 1B), absorbent core(FIG. 1C), or outer liner (FIG. 1D), thus protruding through the innerliner. In a preferred embodiment, the braid is attached to the pad bystitching or adhesive or heat. In the preferred embodiment, the threadscomprising the braid are pressed into the pad body forming “roots”approximately two centimeters in length through the inner liner and intothe pad, and may be unbraided or braided in this area. In an alternateembodiment, the braid is woven integrally with a woven liner layer.

Braid fibers can be made of a variety of materials, including naturalfibers such as cotton, hemp, linen, paper, and combinations thereof,while absorbent core materials include fluff pulp, dried hydrogel (suchas sodium polyacrylate, sodium acrylate, potassium acrylate, or an alkylacrylate), and the like. In the preferred embodiment, the braid fiberswill be made from cotton. The fibers may also be impregnated with avariety of polymers to improve their absorbency. Absorbency is measuredin accordance with the methods described in U.S. Pat. No. 6,700,035(incorporated herein by reference in its entirety), which describesinfiltration, diffusivity and liquid returnability under pressure tests.In the preferred embodiment, the braid fibers will be lined orimpregnated with a synthetic material that will aid in absorption.

Pads are seen as hygiene products--merely functional products devoid ofaesthetic qualities. In contrast, in its most preferred embodiment, thisproduct will be both appealing and feminine. It will be manufactured ina variety of colors, scented and embossed or printed with variousdesigns. Between the materials, the colors, the designs and the scents,this pad will be like attaching a charming sticker to your underwear.

The pad of the invention is exemplified in the following examples.However, the examples are illustrative only, and are not to be construedas limiting.

EXAMPLE 1 Pad Structure

FIG. 1A shows a side view of the pad (1), illustrating the braid (3)attached to the pad (2) roughly in the center of the elongated pad. FIG.1B-D demonstrate attachment to the inner liner (6), the absorbent core(7) and the outer liner (8). FIG. 2A shows a top view of the inner sideof the pad with the braid (3) attached in the middle of the pad (2).FIG. 2B shows the braid attached in the rear portion of the pad. FIG. 2Cshows a braid attached to the end of a “thong” shaped pad. FIG. 3 showsa perspective view.

EXAMPLE 2 Pad Manufacture

In one embodiment, the pad of the invention is manufactured using asanitary napkin pad, and incontinence pad machine. Production can easilyrun a wide range of raw materials and produce sanitary napkins withvarious manufacturing structures because the machine has been designedto assure simple and rapid size changes. In one embodiment, ultrathincores with binders provide a number of fluff layers with an integratedSAP powder layered with non-woven airlaid transition layers. Braidedattachments are incorporated with adhesive on the topsheet prior tofolding, stacking and packing Thong pantyliners with a 180 degree turnare woven directly into the braided string. After the braid isincorporated, the napkins enter a tri-folding, stacking and packingunit, which completes the production process.

EXAMPLE 3 Ultrasonic Sealing

The braided attachment can be added after the sanitary napkin orincontinence pad is assembled. In one embodiment, a braid with threethreads made of cotton and lined with a man-made absorbent material aresewn or sealed by ultrasound to the inner liner of the absorbent pad.The cotton braid is pressed using a press at 7000 kg for 15 minutes. Thebraid is placed in the middle of the sanitary napkin. In one embodimentusing a 24-cm sanitary napkin the braid is placed at 12 cm. The braidwas fixed to the sanitary napkin using ultrasound. Briefly, the braid isunwound at one end to create “roots” about 2 cm long inside the sanitarynapkin through the inner liner and into the absorbent pad. Theun-braided “roots” are heated by ultrasound and adhered to the innerliner leaving the “roots” embedded in the absorbent pad. In oneembodiment the braid is 12 cm long. In a preferred embodiment the braidis 15 cm long. A loose braid can be used to keep the material soft andpliable. A tighter braid makes the material more stiff, thus care mustbe taken to control the tightness of the weave and ensure the braid iscomfortable. In another embodiment the braid could be tapered fromthicker to thinner allowing for maximum absorbance and comfort.

EXAMPLE 4 Pad Underwear

In another embodiment, the pad is configured to provide an entiredisposable thong underwear (FIG. 5). The braid (3) terminates in astretch waistband (5), and the front of the pad is elongated, flared andconnected to the waistband 5. In this instance, the pad (1) is broaderin the front, and tapers towards the braid, thus providing acomfortable, yet disposable underwear and pad combination. In thisconfiguration, the outer surface of the pad is chosen to beaesthetically pleasing and comfortable to wear, but inexpensive tomanufacture. In another embodiment the braid is elongated to form thewaistband. A strip of Velcro™, adhesive or loops along the front edge ofthe pad allows attachment to the waistband at varying configurations.The braid can be a single length up to 100 cm with an adjustable clip atthe end for connection at the 90.degree. turn (9) allowing the wearer tocustomize the length of the braid. In another embodiment a second braidis attached somewhere along the first braid forming a “Y” or “T” backthe wearer can then attach both braids to the front of the pad making acustom waistline. The attachment means can be any suitable structure,including hooks and loops, adhesives, snaps, clips and the like, or canbe a permanent attachment, rather than a removable attachment means, inwhich case, the braids can be highly elasticized to accommodate avariety of sizes.

All citations referenced herein are incorporated by reference in theirentirety.

1. U.S. Pat. No. 3,911,785, H. A. Hood, “Parallel yarn rope.”

2. U.S. Pat. No. 3,975,980, H. A. Hood, “Method and apparatus formanufacturing faired article.”

3. U.S. Pat. No. 4,016,911, R. Looker, “Woven rope.”

4. U.S. Pat. No. 4,380,949, W. Betta, “Braided stranded rope formingmachine.” [002]

5. U.S. Pat. No. 4,533,357, F. E. Hall, “Sanitary napkin construction.”

6. U.S. Pat. No. 5,060,549, M. Beal, “Safety rope for climbing andmanufacturing method therefor.”

7. U.S. Pat. No. 5,067,384, E. Scala, “Braider method and apparatus formanufactured faired rope or cable.”

8. U.S. Pat. No. 5,127,911, E. Baharav, “Sanitary feminine napkin with amechanism for optional contouring.”

9. U.S. Pat. No. 5,169,394, L. D. Jean, “Feminine sanitary napkin.”

10. U.S. Pat. No. 5,743,896, B. M. Parker, “Sanitary napkin having aprotrusion insertable into the posterior rugae of the buttocks.”

11. U.S. Pat. No. 6,613,031, Glasgow, et al., “Sanitary napkin withintergluteal strip.”

12. U.S. Pat. No. 6,676,649, S. Mizutani, “Sanitary napkin having upperand lower absorbent cores.”

13. U.S. Pat. No. 6,700,035, Y. Wataru, “Absorbent article.”

14. U.S. Pat. No. 6,821,270, L. G. Rosenfeld, “Sanitary absorbentarticle.”

15. U.S. Pat. No. 6,997,915, Gell, et al., “Sanitary napkin withadjustable length intergluteal strip.”

16. U.S. Pat. No. 7,056,312, R. L. Metcalft, “Sanitary napkin withabsorbent tab.”

17. U.S. Pat. No. 7,147,628, S. Drevik, “Absorbent article with improvedliquid handling ability.”

18. U.S. Pat. No. 7,196,241, Kinoshita, et al., “Sanitary napkins withcompressed grooves.”

19. U.S. Pat. No. 7,235,708, Guidotti, et al. “Absorbent articlecomprising an absorbent structure.”

20. US2005229770, Smeets, et al., “Endless rope.”

21. US2005277088, D. E. Fischer, “Reinforced gingival retraction cord.”

22. EP 1332744, Glasgow, et al., “Sanitary napkin with interglutealstrip.”

23. WO9004956, B. C. Muller, “Sanitary napkin.”

1. A sanitary pad, comprising: a) a pad body having an elongated shapewith a major axis and a minor axis and comprising an inner liner abovean absorbent core above an outer liner; and b) an elongated braidattached to said pad body about mid way along the minor axis, whereinsaid braid comprises at least three strands of braided fiber and isabsorbent.
 2. The sanitary pad of claim 1, wherein the strands of fiberare selected from the group consisting of cotton, hemp, wool, wood-pulp,cellulose, polyacrylate, polypropylene, polyester, polyethylene,polyurethane, LYCRA® and combinations thereof
 3. The sanitary pad ofclaim 1, wherein the braid is made from two different fibers, one ofwhich is absorbent.
 4. The sanitary pad of claim 1, wherein at least oneof the fibers is cotton.
 5. The sanitary pad of claim 1, wherein theabsorbent material is selected from the group consisting of a superabsorbent polymer, polyacrylic acid, polyacrylamide copolymer, ethylenemaleic anhydride copolymer, cross-linked carboxy-methyl-cellulose,polyvinyl alcohol copolymers, cross-linked polyethylene oxide, sodiumpolyacrylate, microporous cellulose, carbohydrate acrylic copolymer, andstarch grafted copolymer.
 6. The sanitary pad of claim 1, wherein thebraid tapers from a thick portion near the pad body to a thin portionaway from the pad body.
 7. The sanitary pad of claim 1, wherein thebraid is attached to the pad body at the intersection of the major andminor axes.
 8. The sanitary pad of claim 1, wherein the braid isattached to the pad body along the major axis between the rear of thepad and the intersection of the major and minor axes.
 9. The sanitarypad of claim 1, wherein the braid further comprises an unbraided portionof thread that is attached to the pad body.
 10. The sanitary pad ofclaim 1, wherein the braid is stitched to the pad body.
 11. The sanitarypad of claim 1, wherein the braid is adhered to the pad body.
 12. Thesanitary pad of claim 1, wherein the braid is attached to the outerliner of the pad body and protrudes through the absorbent core and innerliner.
 13. The sanitary pad of claim 1, wherein the braid is attached tothe absorbent core of the pad body and protrudes through the innerliner.
 14. The sanitary pad of claim 1, wherein the braid is attached tothe inner liner of the pad body.
 15. The sanitary pad of claim 1,wherein the braid is 10-30 centimeters in length.
 16. The sanitary padof claim 1, wherein the outer liner is imprinted with designs, and thepad body is impregnated with perfume.
 17. The sanitary pad of claim 1,wherein the outer liner is a color other than white.
 18. A sanitary padcomprising an elongated pad body having a major and minor axis, saidelongated pad body having an absorbent core, and a braid attached tosaid elongated pad body at about the mid point of the minor axis andbetween the rear of the elongated pad body and the intersection of themajor and minor axes, said braid comprising at least three braidedfibers and an absorbent material and being greater than 10 cm in length.19. An improved sanitary pad having a pad body, the improvementcomprising a braid attached to the pad body and positioned to fitintergluteally and comprising at least three braided fibers and anabsorbent material.